That a 23-6 victory over Ireland secured England a seventh straight Six Nations championship, and sixth grand slam in that time, suggests it was all but inevitable. In fact, although Katy McLean's side started as strong favourites, it was a win and a championship as hard earned as any in that run, and as such testimony to the huge improvement and growing strength in depth of women's rugby union.

Delighted as they were with their team's success, McLean and the head coach, Gary Street, took almost as much pleasure in the closeness of the contest. Held level until well beyond the break by a terrific young Irish side who had beaten Italy, Wales and Scotland, England's superior fitness and stronger bench eventually told when the stand-off McLean struck from distance and the replacement hooker Amy Turner drove over from close range.

"As a player you want to be in tight games, and going to France last week [and winning 15-3] and coming here and having to dig in is exactly what we want," said McLean. "It only shows the game in a good way – the skills' improvement and the fitness."

Street agreed. "Technically and tactically the women's game is making huge strides, and the detractors are usually people who haven't seen it recently. The key is giving people the opportunity to see that for themselves, and the RFU is bending over backwards to do that."

In that respect it was something of a shame this game was staged in the hospitable but somewhat basic Esher club ground, because in every respect it was worthy of a grander stage. Back in the autumn Street's email inbox was flooded with congratulations from Twickenham spectators who stayed to watch the game between England and the world champions New Zealand staged following the men's match between Australia and the Barbarians.

"Many said they were only going to stay a few minutes and ended up watching the whole of one of the best games they'd ever seen," said Street. "What they don't realise is that the women's game is now at a stage when a lot of players have been playing since they were six or seven.

"They're still amateurs of course, so they train before and after work, but their dedication is incredible and it's reflected in their skills, in their handling, kicking, tackling and fitness." It did not help England that an already long injury list coming into the game was lengthened further when the outstanding flanker Maggie Alphonsi was forced off in the first half with a knee problem. A pack accustomed to dominate received as good as it got in both set piece and loose from their Irish counterparts, and it was only in the backs where England's greater power and pace made them consistently the more threatening side.

Even then McLean and the centre Rachael Burford, also outstanding, had to work as hard in defence as they did in attack, but the team's determination to preserve their record of not having conceded a try in this tournament was impressive.

"Defence is one of our strengths, it's a testament to the work our coaches do with us that it's difficult for other teams to break us down," said McLean. "It was something we focused on coming into this game and it stood us in good stead."